bited by some other
stronger one, does not immediately or remotely express itself in action
of some kind. There is no one of those complicated performances in the
convolutions of the brain to which our trains of thought correspond,
which is not a mere middle term interposed between an incoming
sensation that arouses it and an outgoing discharge of some sort,
inhibitory if not exciting, to which itself gives rise. The structural
unit of the nervous system is in fact a triad, neither of whose
elements has any independent existence. The sensory impression exists
only for the sake of awaking the central process of reflection, and the
central process of reflection exists {114} only for the sake of calling
forth the final act. All action is thus _re_-action upon the outer
world; and the middle stage of consideration or contemplation or
thinking is only a place of transit, the bottom of a loop, both whose
ends have their point of application in the outer world. If it should
ever have no roots in the outer world, if it should ever happen that it
led to no active measures, it would fail of its essential function, and
would have to be considered either pathological or abortive. The
current of life which runs in at our eyes or ears is meant to run out
at our hands, feet, or lips. The only use of the thoughts it occasions
while inside is to determine its direction to whichever of these organs
shall, on the whole, under the circumstances actually present, act in
the way most propitious to our welfare.

The willing department of our nature, in short, dominates both the
conceiving department and the feeling department; or, in plainer
English, perception and thinking are only there for behavior's sake.

I am sure I am not wrong in stating this result as one of the
fundamental conclusions to which the entire drift of modern
physiological investigation sweeps us. If asked what great
contribution physiology has made to psychology of late years, I am sure
every competent authority will reply that her influence has in no way
been so weighty as in the copious illustration, verification, and
consolidation of this broad, general point of view.

I invite you, then, to consider what may be the possible speculative
consequences involved in this great achievement of our generation.
Already, it dominates all the new work done in psychology; but {115}
what I wish to ask is whether its influence may not extend far beyond
the limits of psyc